What did I drill through?

[Henningelvis]

I also live in a 1960s house with a basement. Concrete breezeblocks in the walls and visible cast iron pipes. I don't think you have destroyed anything.

 

[Jocke Best]

If you had drilled through such a cast iron pipe, it would have rattled something terrible and taken quite a while with a regular hammer drill and concrete bit. You can relax.

 

[Bjurn25]

How nice! Thank you so much for the help! I feel much calmer!

 

[Demmpa]

Now I have listened at the hole, and hear nothing from the hole, but I hear water running in the room next to it, and saw this. Is this a drainpipe?

Looks like someone has painted the white drain pipes, first-generation plastic pipes, also called eggshell pipes, this is because they are brittle and crack easily. They are glued at the joints.